LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 2004 >> Century Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 116 (HVAC Systems - Manual) >> Diagnostic Information & Procedures >> Too Hot in Vehicle

Too Hot in Vehicle

WARNING: This page is about a different car, the 2004 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.
Too Hot in Vehicle

Step Action Values Yes No
Schematic Reference: HVAC Schematics 
Connector End View Reference: HVAC Connector End Views 
DEFINITION: The temperature cannot be adjusted, or the cooling is insufficient during A/C operation.
1 Did you perform the HVAC Diagnostic System Check? - Go to Step 2  Go to Symptoms - HVAC Systems - Manual 
2
  1. Turn ON the ignition, with the engine OFF.
  2. Place the blower motor switch in each speed position.
Does the blower motor operate in any of the speed positions?		 - Go to Step 3  Go to Blower Motor Inoperative 
3 Does the blower motor operate at the desired speeds? - Go to Step 4  Go to Blower Motor Malfunction 
4 When the A/C is ON, does the customer concern occur? - Go to Step 5  Go to Step 7 
5
  1. Start the engine.
  2. Place the blower motor switch in the maximum speed position.
  3. Place the mode switch in the MAX position.
Does the recirculation door move to the recirculation position?		 - Go to Step 6  Go to Air Delivery Improper 
6
  1. Place the blower motor switch in the maximum speed position.
  2. Place the mode switch in the MAX position.
  3. Place the temperature switch in the coldest position.
Does the A/C compressor operate?		 - Go to Step 7  Go to HVAC Compressor Clutch Does Not Engage 
7 Perform the refrigerant system performance test. Refer to Air Conditioning (A/C) System Performance Test in Heating, Ventilation and Air Conditioning.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 8 
8
  1. Observe the drive shaft of the air temperature actuator.
  2. Place the air temperature switch from the coldest position to the warmest position.
Does the air temperature actuator drive shaft rotate at all?		 - Go to Step 9  Go to Step 10 
9 Inspect the air temperature door and the air temperature actuator for the following conditions:
  • A misaligned air temperature actuator. Refer to Air Temperature Actuator Replacement .
  • Broken or binding linkages or air temperature door
  • An obstruction that prevents the air temperature door from operating within its full range of motion
  • Missing seals to the air temperature door
  • Misaligned seals to the air temperature door

Did you find and correct the condition?		 - Go to Step 18  Go to Step 10 
10 Test the control A and control B circuits of the air temperature actuator for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 11 
11
  1. Connect a test lamp between the air temperature actuator control A circuit and the control B circuit
  2. Move the air temperature control from hot to cold
Does the test lamp illuminate with each command?		 - Go to Step 14  Go to Step 12 
12 Test the ignition 3 voltage circuit of the HVAC control module for an open, high resistance, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 13 
13 Test the ground circuit of the HVAC control module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 15 
14 Inspect for poor connections at the harness connector of the air temperature actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 16 
15 Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 17 
16 Replace the air temperature actuator. Refer to Air Temperature Actuator Replacement .
Did you complete the replacement?		 - Go to Step 18  -
17 Replace the HVAC control module. Refer to HVAC Control Assembly Replacement .
Did you complete the replacement?		 - Go to Step 18  -
18 Operate the system in order to verify the repair.
Did you correct the condition?		 - System OK Go to Step 2 
scientia non olet · About LEMON Manuals